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Abstract  A reporter gene assay revealed that promoters derived from Synechococcus PCC7942 (S.7942) psbAI and Synechocystis PCC6803 (S.6803) psbAII were suitable for the expression of foreign ribulose-bisphosphate carboxylase (RuBisCO; EC 4.1.1.39) in S.7942 cells. Transformational vectors with a promoter and a foreign RuBisCO gene, cvrbc originated from Allochromatium vinosum, were constructed on a binary vector, pUC303, and introduced to S.7942 cells. When the cvrbc was expressed with the S.7942 psbAI promoter, the total RuBisCO activity increased 2.5- to 4-fold than that of the wild type cell. The S.6803 psbAII promoter increased the activity of the transformant 1.5–2 times of that of wild type cell. There was a significant increase in the rate of photosynthesis depending on the increase of RuBisCO activity. The maximum rate of photosynthesis of the transformant cell was 1.63 times higher than that of the wild type under the illumination of 400 μmol m−2 s−1, at 20 mM bicarbonate and at 30 °C. Although the photosynthesis of the higher plant is limited by the ability of photosystems under high irradiance and the high CO2 concentration, that of the S.7942 cell is limited by the RuBisCO activity, even at high CO2 concentrations and under high irradiance. [ABSTRACT FROM AUTHOR]

Abstract Most insects have telomeres that consist of pentanucleotide (TTAGG) telomeric repeats, which are synthesized by telomerase. However, all species in Diptera so far examined and several species in other orders of insect have lost the (TTAGG)n repeats, suggesting that some of them recruit telomerase-independent telomere maintenance. The silkworm, Bombyx mori, retains the TTAGG motifs in the chromosomal ends but expresses quite a low level of telomerase activity in all stages of various tissues. Just proximal to a 6–8-kb stretch of the TTAGG repeats in B. mori, more than 1000 copies of non-LTR retrotransposons, designated TRAS and SART families, occur among the telomeric repeats and accumulate. TRAS and SART are abundantly transcribed and actively retrotransposed into TTAGG telomeric repeats in a highly sequence-specific manner. They have three possible mechanisms to ensure specific integration into the telomeric repeats. This article focuses on the telomere structure and telomere-specific non-LTR retrotransposons in B. mori and discusses the mechanisms for telomere maintenance in this insect. [ABSTRACT FROM AUTHOR]

Summary. Long electropherotype with Subgroup I specificity is a common feature of animal rotaviruses. In an epidemic of infantile gastroenteritis in Manipur, India, long but SG I strains predominated in the outbreak in the year 1987?88. One such strain isolated from that region, following the outbreak had G9P [19] specificity. As this is a rare combination, the gene sequences encoding VP4, VP6, VP7, NSP1, NSP2, NSP3, NSP4 and NSP5 of this strain were analyzed. All these genes except VP7 were closely related to porcine rotaviruses (95?99% identity at amino acid level) and clustered with the porcine strains in phylogenetic analysis. In addition, it had subgroup I nature and belonged to NSP4 genotype B which is characteristic of animal rotaviruses. This is the first report of a rotavirus with VP6 and NSP4, two crucial proteins thought to be involved in host range restriction and pathogenicity, were of porcine origin and caused diarrhoea in a human host. Among the genes of this strain sequenced so far, only VP7 had highest identity to human strains at amino acid level. This study suggests reassortment may be occurring between human and other animal strains and some of the reassortant viruses may be virulent to humans. [ABSTRACT FROM AUTHOR]

Abstract??Seedlings planted on degraded lands experience high leaf temperature in daytime because of the lack of vegetation shading. The effect of high temperature on the photosynthetic capacity was investigated inDipterocarpus obtusifoliusTeijsm.exMiq. andD. chartaceusSym. seedlings planted on degraded sandy soils in southern Thailand. Neither species showed decrease in photosynthetic capacity at leaf temperature over 38 ?C as compared to that at 28 ?C.D. obtusifoliusshowed higher photosynthetic capacity at high temperatures. Enhanced photosynthetic capacity at high temperatures would be a key for high photosynthetic performance ofD. obtusifoliusplanted on degraded sandy soils. [ABSTRACT FROM AUTHOR]

We report the investigation of the performance of an interleaved Reed-Solomon forward error correction code in the presence of optical power transients in a DWDM transmission system for the first time. These transients were generated by adding-dropping channels in an erbium-doped fiber amplifier or Raman amplified systems. [ABSTRACT FROM PUBLISHER]

We describe dense wavelength-division-multiplexing (DWDM) operation of a reconfigurable optical add-drop multiplexer subsystem module employing silica waveguide technology that is suitable for use with both fixed-wavelength and wavelength-selectable add-drop transceivers. We illustrate its use in providing modular growth in high channel-count DWDM systems. [ABSTRACT FROM PUBLISHER]

We investigate the cascadability and transient effects of an micro-electromechanical-systems-based 64-channel blocker. We observe no transient effect due to the blocker. We limited our study to ten cascades and observe negligible optical power penalty with or without the 7-dB maximum allowable equalization for both nonreturn-to-zero and return-to-zero pulses. [ABSTRACT FROM PUBLISHER]

Mechanical properties of high quality tetragonal hen egg-white lysozyme single crystals which are one type of protein crystal were investigated by the indentation method. The indentation marks were clearly observed on the crystal surface and no elastic recovery of them occurred. The value of the micro-Vickers hardness in the wet condition was estimated to be about 20 MPa at room temperature. The hardness greatly depended on the amount of intracrystalline water (mobile water) contained in the crystals. The hardness increased with increasing evaporation time to air at room temperature. It reached the maximum at about 260 MPa, which is 13 times as much as that in the wet condition. The origin of such a change in hardness was explained in terms of the dislocation mechanisms in lysozyme single crystals. [ABSTRACT FROM AUTHOR]

We investigated dislocation motions in C60 crystals after indentation, by x-ray topography and etching method. A rosette pattern was observed around an indentation after etching. The dislocations in the rosette were moved by thermal annealing and the positions in the dislocations were measured before and after annealing by the double etching method. The annealing temperature dependence of dislocation motions was measured in the temperature range 490-610 K. The characteristics of dislocation motion showed dislocation locking due to impurity atmosphere. It was concluded that oxygen and oxide of C60 molecules could lock the dislocations. Moreover, a pair of pits in the rosette pattern were observed after annealing. It corresponded to a pair of Shockley's partial dislocations. [ABSTRACT FROM AUTHOR]