Genetically engineered active Qbeta replicase in rabbit reticulocyte cell-free system: a fusion protein of EF-Tu and EF-Ts is functional as the subunit of Qbeta replicase

Qbeta replicase functioning in Escherichia coli is an RNA-dependent RNA polymerase composed of one phage-coded subunit and three host-coded proteins: ribosomal protein S1, and protein elongation factors EF-Tu and EF-Ts. Qbeta replicase lacking ribosomal protein S1 (alpha-less replicase) is capable of replicating some small RNAs. We attempted to create functional alpha-less replicase by co-expression of the mRNAs that code for the subunits of alpha-less replicase in a rabbit reticulocyte cell-free translation system. Replicase activity, however, could not be detected when both EF-Tu and EF-Ts were co-expressed with the phage-coded subunit. On the other hand, active alpha-less replicase was obtained when an EF-Ts-EF-Tu fusion protein was co-expressed with the phage-coded subunit. Consequently, we succeeded in generating genetically engineered active alpha-less Qbeta replicase which functions in a eukaryotic cell-free system.     

A novel gene delivery system in plants with calcium alginate micro-beads

We have produced micrometer-sized calcium alginate beads referred to as "bio-beads" that encapsulate plasmid DNA molecules carrying a reporter gene. In order to evaluate the efficiency of the bio-beads in mediating genetic transfection, protoplasts isolated from cultured tobacco cells (BY-2) were transfected with bio-beads containing a plasmid that carries the modified green fluorescent protein gene CaMV35S-sGFP. With the bio-beads treatment, approximately ten-fold higher GFP expression was observed after 24 h incubation compared to that with the conventional method using a naked plasmid solution. Transfection was up to 0.22% efficient. These results indicate that bio-beads have a possibility for efficient transformation in plants.     

MRF-based texture segmentation using wavelet decomposed images

In recent textured image segmentation, Bayesian approaches capitalizing on computational efficiency of multiresolution representations have received much attention. Most of the previous researches have been based on multiresolution stochastic models which use the Gaussian pyramid image decomposition. In this paper, motivated by nonredundant directional selectivity and highly discriminative nature of the wavelet representation, we present an unsupervised textured image segmentation algorithm based on a multiscale stochastic modeling over the wavelet decomposition of image. The model, using doubly stochastic Markov random fields, captures intrascale statistical dependencies over the wavelet decomposed image and intrascale and interscale dependencies over the corresponding multiresolution region image.     

Thermodynamics of iron oxide in Fe x O-dilute CaO + Al2O3 + MgO + Fe x O slags at 1873 K

In order to determine the ferrous and ferric ion capacities: 3

Input system for part model in CAD from coloured hand-written illustration with use of ITV

An input system for CAD is developed to construct a part model within a computer from a hand-written sketch. The sketch is drawn based on the technical illustration method. The shape of the input part is constructed by the combination of cuboids and cylinders at present. A coloured illustration is adopted for the ease of the shape recognition and for the input of the technological information.

The illustration is fed into the computer via a black and white ITV. Colours are identified referring to the brightness of the input image. The constitutive bodies, the geometric element with the technological information and the content of the technological information are recognized through image processing such as noise filtering, thinning of the contours, detection of lines and so on. The input system outputs a set of commands to the modelling system. The integrated part model which includes not only the geometrical information but also the technological information of the part is constructed by the connected modelling system CIMS/MODE.

The combination of the input system and the modelling system can support the designer to construct the detailed part model within the computer effectively. It is expected to extend the ability of the input system to identify general hand-written illustrations so that the input method will be more practical and useful.     

A novel transfection method for mammalian cells using calcium alginate microbeads

The direct transfer of genetic materials into mammalian cells is an indispensable technique. We have developed calcium alginate (CA) microbeads which can deliver plasmid DNAs and yeast artificial chromosomes into plant and yeast cells. In this paper, we demonstrate the effective transfection of mammalian cells by CA microbeads immobilizing plasmid DNAs. The transfection was performed using the pEGFP-C1 plasmid containing the cytomegalovirus (CMV) promoter and enhanced green fluorescent protein (EGFP) gene. The transient expression of EGFP was observed 24 h after transfection. The expression efficiency was maximum when the concentration of sodium alginate was 1% and the amount of plasmid DNA was increased to 100 microg. The expression efficiency of our method using CA microbeads is 2-10 times higher than that of the polyethylene glycol (PEG) method. Our results suggest that the CA microbead mediated transfection of mammalian cells effectively delivers genetic materials into mammalian suspension cells.     

Cell cycle analysis of Chinese hamster ovary cells stimulated by phosphatidic acid in serum-free culture

When recombinant Chinese hamster ovary cells were treated with pertussis toxin or genistein, not only lysophosphatidic acid (LPA) but also phosphatidic acid (PA) failed to stimulate progression through the cell cycle in serum-free culture, suggesting that PA and LPA induce cell growth through the same signal transduction pathway. Cell cycle analysis also indicates that cell growth promoted by PA results in enhanced protein production.     

Quasicrystals as cluster aggregates

Quasicrystals are solids that exhibit symmetries long thought forbidden in nature. Since their discovery in a rapidly solidified Al-Mn alloy in 1984, the central issue in the field has been to understand why they form. Are they energetically stable compounds or stabilized by entropy? In recent years, major strides have been made in determining atomic structure, largely by direct imaging using advanced electron microscopy. One system is now known to be energetically stabilized, and quasicrystals are therefore firmly established as a new physical state of matter. They represent a unique packing of atomic clusters some tens of atoms in size, with substantial localized fluctuations, referred to as phasons. Understanding phasons may in future allow their unique macroscopic properties to be tailored for useful materials applications.     

Defect levels in chromium-doped silicon

The transient capacitance technique has been used to study the chromium-related levels in the silicon band gap. Chromium was diffused at temperature of 1100 and 1150°C for 0.5 and 3 hr. Five different levels at E_c?0.11 eV, E_c?0.21 eV, E_c?0.28 eV, E_c?0.36 eV and E_c?0.45 eV were obtained from the Arrheniu plots of the electron thermal-emission rates. The number of levels in the upper half of the band gap decreased from five to two with an increase of Cr-diffusion period. Two levels were located at E_c?0.20 eV (donor) and E_c?0.43 eV (acceptor). A donor level was also observed at E_v + 0.25 eV. The donor level was not affected by the diffusion condition. The majority carrier capture cross sections of the three dominant levels have been measured by the transient capacitance technique modified by the pulse transformer. The values were σ_n = 4.1 × 10^?15 cm² for the upper donor at E_c?0.20 eV, σ_n = 2.0 × 10^?16 cm² for the acceptor at E_c ?0.43 eV and σ_p = 9.1 × 10^?18 cm² for the lower donor at E_v + 0.25 eV, and were independent of temperature. The three dominant levels are due to distinct chromium centers.     

A self-organizing map with twin units capable of describing a nonlinear input-output relation applied to speech code vector mapping

This paper describes a new type of self-organizing map (SOM) with twin units as opposed to the single unit type conventional SOM proposed by Kohonen. The present self-organizing map with twin units (TW-SOM) can describe a nonlinear input-output relation with high accuracy. It is applied to voice conversion problem from bone conduction voice to air conduction voice (nonlinear code vector mapping), and its superiority over the conventional method using Linde-Buzo-Gray (LBG) algorithm is discussed. The tone quality of the converted voice is examined not only from the quantization distortion viewpoint, but also from the auditory sensation viewpoint through actual listening tests. The enhancement of the tone quality was experimentally confirmed.