Ribosomal Synthesis of Peptides with C‐Terminal Lactams,Thiolactones, and Alkylamides

All change at the C terminus : We have established a novel methodology for the ribosomal synthesis of peptides featuring C‐terminal cyclization and various modifications, including macrocyclization, by making use of genetic code reprogramming. The C‐terminal amide modification of linear and cyclic peptides should enhance their physiological stabilities, and open up the possibility of developing new drug‐like peptides.

     

A data taking system with low power consumption for cosmic ray research

We have succeeded in operating the 64 m² solar neutron detector based on 24 W power consumption. The detector has been operated at the Mount Norikura Cosmic Ray Observatory (2770 m) with the small amount of power delivered by solar cell arrays and windmills, without generator service, throughout severe winter of 2003–2004. The results of our experiences are described.     

Rapid disappearance of AML1/ETO fusion transcripts in patients with t(8;21) acute myeloid leukemia following bone marrow transplantation and chemotherapy

A new analogue of recombinant human growth hormone (hGH), hGH des(1-6,14) was expressed in Escherichia coli, refolded and purified to homogeneity. The mutation decreased the hormone's ability to bind lactogenic and somatogenic receptors through its site 1, and almost completely abolished its ability to bind these receptors through site 2, as evidenced by both binding and gel-filtration experiments. More specifically, the binding to prolactin receptors (PRLRs) from various species or their soluble recombinant extracellular domains (ECDs) was decreased 1.5-4-fold, whereas the binding to hGH receptor (hGHR) was decreased 10-85-fold. These changes caused an almost total loss of hormone agonistic activity in several in vitro bioassays and subsequently, the hGH des(1-6,14) analogue acquired antagonistic properties. This antagonistic activity was dependent upon modification of site 1. In those cases in which the binding was reduced only slightly, e.g. binding to rabbit PRLRs, hGH des(1-6,14) acted as a strong antagonist, whereas in others in which the binding of site 1 was reduced to a higher degree, such as other PRLRs and, in particular, hGHR, the antagonistic activity was correspondingly weaker. Circular dichroism spectra of the analogue suggested that these changes do not result from a decrease in overall alpha-helix content, but rather from minor local structural modifications at the N-terminus.     

Differentiation of Allium carlaviruses isolated from different parts of the world based on the viral coat protein sequence

Common primers which amplify the 3' terminal genomic RNAs of Allium carlaviruses were designed based on the nucleotide sequence of shallot latent virus (SLV), garlic latent virus (GLV) and garlic common latent virus (GCLV). A total of fifteen cDNAs encoding the coat protein (CP) of the carlaviruses, including the biologically identified isolates SLV, GLV and GCLV as well as viruses from infected Allium plants cultivated in different parts of the world, were amplified by RT-PCR with the common primers. The cDNAs were then cloned and sequenced. The predicted viral CP amino acid sequence as well as the nucleotide sequence revealed that SLV and GLV, previously considered as separate viruses on the basis of their biological and physical properties, belong to the same species of the genus Carlavirus. Both viruses are clearly differentiated from GCLV. In addition, every SLV and GLV isolate from the Allium plants in Taiwan showed characteristic and common variations in their CP sequences, suggesting the possible presence of geographical variants. However, no apparent sequence variations of SLV and GLV related to their host plant species, including A. sativum, A. wakegi, A. chinense, A. fistulosum, A. cepa and A. ampeloprasum, were observed. These findings suggested that the sequence variations observed in the respective virus isolates do not correlate with the specificity of their infectivities for Allium species.     

Discriminative learning quadratic discriminant function for handwriting recognition

In character string recognition integrating segmentation and classification, high classification accuracy and resistance to noncharacters are desired to the underlying classifier. In a previous evaluation study, the modified quadratic discriminant function (MQDF) proposed by Kimura et al. was shown to be superior in noncharacter resistance but inferior in classification accuracy to neural networks. This paper proposes a discriminative learning algorithm to optimize the parameters of MQDF with aim to improve the classification accuracy while preserving the superior noncharacter resistance. We refer to the resulting classifier as discriminative learning QDF (DLQDF). The parameters of DLQDF adhere to the structure of MQDF under the Gaussian density assumption and are optimized under the minimum classification error (MCE) criterion. The promise of DLQDF is justified in handwritten digit recognition and numeral string recognition, where the performance of DLQDF is comparable to or superior to that of neural classifiers. The results are also competitive to the best ones reported in the literature.     

Regional distribution in the fatty acids of triacylglycerols and phospholipids within soybean seeds (Glycine max L.)

The fatty acid distribution of triacylglycerols (TAG) and major phospholipids (PL) within soybean seeds (Glycine max L.) was investigated in relation to their tocopherol contents. The lipids extracted from four cultivars were separated by thin‐layer chromatography into seven fractions. Tocopherols were predominantly detected in the axis, followed by cotyledons and seed coat. The major lipid components were TAG and PL, while hydrocarbons, steryl esters, free fatty acids and diacylglycerols (sn‐1,3 and sn‐1,2) were also present in minor proportions. With a few exceptions, the dominant PL components were phosphatidylcholine, followed by phosphatidylethanolamine or phosphatidylinositiol. Significant differences (p <0.05) in fatty acid distribution existed when different soybean cultivars were examined. However, the principal characteristics of the fatty acid distribution in the TAG were evident among four cultivars; unsaturated fatty acids were predominantly concentrated in the sn‐2 position, and saturated fatty acids primarily occupied the sn‐1 or sn‐3 position in the oils of the soybeans.     

Autonomous collaborative environment for project-based learning

The importance of integrating different disciplines of information science and technology is growing for the realization of an information system which works robustly in the real world. Such a system should be achieved by integrating different disciplines, since it is difficult to cover all areas in information science and technology by only one person or group. In order to support collaboration, the autonomous collaborative environment for project- based learning was developed. The environment comprises the workshop “A Hundred Hour Workshop” and the community site “WS100H.NET”. Novel interdisciplinary technology, fusion of recognition and parallel computation was successfully developed whose collaboration process was autonomous.