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1

Preparation of Polythiophene Films Showing Optical Activity by Electrochemical Polymerisation in Cholesteric Liquid Crystal Containing Coumarine

100%

Hayashi H. , Goto H.

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tom Vol. 46

42--47

EN

We carried out electrochemical polymerisation in a cholesteric liquid crystal electrolyte solution. The polymer film prepared in the cholesteric liquid crystal showed chiropticality even though its monomer is an achiral. The surface morphology of the polymer was observed with polarising optical microscopy. Optical and electric properties were examined by UV-vis optical absorption, circular dichroism spectroscopy, and cyclic voltammetry.

2

Synthesis of new chiral inducer and preparation of semi-conducting polymer films showing fingerprint structure

80%

Hayashi H. , Kawabata K. , Goto H.

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tom Vol. 8

6--12

EN

We synthesised a rod like shaped new chiral inducer to construct chiral liquid crystal electrolyte solution. Next, electrochemical polymerisation was carried out in the chiral liquid crystal electrolyte solution. The surface morphology of the polymers were observed with polarising optical microscopy. Synthesis of the new chiral inducer and preparation of semi-conducting thin film in the cholesteric liquid crystal electrolyte solution were performed.

3

The spike-timing-dependent plasticity function based on a brain sequential learning system using a recurrent neuronal network

80%

Ogata G. , Natsume K. , Ishizuka S. , Hayashi H.

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2010

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tom Vol. 4, No. 2

25-30

EN

This paper examines the spike-timing-dependent plasticity (STDP) at the synapses of the medial entorhinal cortex (EC) and the dentate gyrus (DG) in the hippocampus. The medial and lateral ECs respectively convey spatial and non-spatial information to the hippocampus, and the DG of the hippocampus integrates or binds them. There is a recurrent neuronal network between the EC and the hippocampus called the EC-hippocampus loop. A computational study has shown that using this loop and STDP phenomena at the recurrent EC synapse, sequential learning can be accomplished. But the STDP functions at the synapses of the EC and DG have not yet been studied by neurophysiological experiments. Experiments on STDP phenomena were performed in rats. The STDP function was asymmetrical in the EC synapse and symmetrical in the DG. The medial EC mainly processes the time-series signals for spatial information about visual landmarks when a rat is running in an environment, the lateral EC processes their features, and the DG binds or integrates the information on the positions and features of the landmarks. Thus, the EC-hippocampus loop processes sequential learning of spatial and non-spatial information in parallel, and the DG binds or integrates the two kinds of signals. A system based on this biological phenomenon could have similar characteristics of parallel processing of object features and positions, and their binding.

4

Preparation of a Ferroelectric Liquid Crystal Electrolyte Solution

70%

Ito T. , Jo T. , Dong J. , Hayashi H. , Goto H.

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tom Vol. 46

1--8

EN

A ferroelectric liquid crystal was synthesised. We attempted electrochemical polymerisation in ferroelectric liquid crystal.

5

A simple local navigation system inspired by hippocampal function and its autonomous mobile robot implementation

70%

Miki T. , Hayashi H. , Goto Y. , Watanabe M. , Inoue T.

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2010

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tom Vol. 4, No. 2

31-38

EN

We propose a practical simple local navigation system inspired by the sequence learning mechanism of the entorhino-hippocampal system. The proposed system memorizes a route as sequences of landmarks in the same way humans do. The proposed local navigation system includes a local route memory unit, landmark extraction unit, and learning-type matching unit. In the local route memory unit, the concept of the sequence learning mechanism of the entorhino-hippocampal system is implemented using a fully connected network, while a sequence of landmarks is embedded in the connection matrix as the local route memory. This system has two operation modes: learning and recall modes. In learning mode, a sequence of landmarks, i.e. a local route, is represented by enhanced loop connections in the connection matrix. In recall mode, the system traces the stored route comparing current landmarks with the stored landmarks using the landmark extraction and learning-type matching units. The system uses a prospective sequence to match the current landmark sequence with the recalled one. Using a prospective sequence in the route comparison allows confirmation of the correct route and deals with any slight change in the current sequence of landmarks. A certainty index is also introduced for judging the validity of the route selection. We describe a basic update mechanism for the stored landmark sequence in the case of a small change in the local route memory. The validity of the proposed system is confirmed using an autonomous mobile robot with the proposed navigation system.

6

Is a genetic defect in Fkbp6 a common cause of azoospermia in humans?

41%

Miyamato T. , Sato H. , Yogev L. , Kleiman S. , Namiki M. , Koh E. , Sakugawa N. , Hayashi H. , Ishikawa M. , Lamb D. J. , Sengoku K.

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nr 4

EN

FK506-binding protein 6 (Fkbp6) is a member of a gene family containing a prolyl isomerase/FK506-binding domain and tetratricopeptide protein-protein interaction domains. Recently, the targeted inactivation of Fkbp6 in mice has been observed to result in aspermic males and the absence of normal pachytene spermatocytes. The loss of Fkbp6 results in abnormal pairing and a misalignment of the homologous chromosomes, and in non-homologous partner switches and autosynapsis of the X chromosome cores in meiotic spermatocytes. In this study, we analyzed whether human FKBP6 gene defects might be associated with human azoospermia. We performed a mutation analysis in all the coding regions of the human FKBP6 gene in 19 patients with azoospermia resulting from meiotic arrest. The expression of the human FKBP6 gene was specific to the testis, and a novel polymorphism site, 245C → G (Y60X) could be found in exon 3. Our findings suggest that the human FKBP6 gene might be imprinted in the testis based on an analysis using two polymorphism sites.