Cellular and transcriptional responses of yeast to the cleavage of cytosolic tRNAs induced by colicin D

Colicin D is a plasmid‐encoded antibacterial protein that specifically cleaves the anticodon loops of four Escherichia coli tRNA^Arg species. Here, we report that the catalytic domain of colicin D, which is expressed in Saccharomyces cerevisiae, impairs cell growth by cleaving specific tRNAs. DNA microarray analysis revealed that mating‐related genes were upregulated, while genes involved in a range of metabolic processes were downregulated, thereby impairing cell growth. The pheromone‐signalling pathway was activated only in α cells by tRNA cleavage, which was not observed in ‘a’ cells or diploid cells. On the basis of these results and on the recent identification of two killer toxins that cleave specific tRNAs, the relationship between tRNA depletion and the resultant cellular response is discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

High-precision voltage-measuring method using fast sampled data for electric power systems

Control and protection equipment in power systems requires higher sensitivity and operational reliability to meet today's changing power system requirements. The voltage-measuring deviation requirement for advanced voltage and var control equipment is less than 0.1 percent under conditions of harmonic distortion in the voltage waveform and power-system frequency variation. Studies on digital signal processing suitable for electric power systems showed that these requirements are satisfied using fast sampling and very fast 32-bit floating point operations by a Digital Signal Processor (DSP). This paper describes the design philosophy of a high-precision power system voltage-measuring method using fast sampled data. In addition, total voltage-measuring deviation characteristics under a combination of the techniques are described along with digital filter characteristics, frequency-measuring deviation characteristics, frequency variation versus gain-compensation characteristics of a digital filter, and peak value operating principles.     

A breakthrough to the plasma deposited dry-developable e-beam resist

This paper presents the preliminary results of efforts to improve dry processed electron beam resist materials using plasma polymerization coating technology. Three approaches investigated were chemical susceptibility modification, the use of multilayer resist structures, and the effect of grafting reactions.     

The effect of repeating load on the crack growth initiation and crack propagation in delayed failure

The delayed failure test under repeating load was carried out with pre-cracked specimen. The incubation time and the crack propagation rate were correlated with the stress intensity factor K.

The incubation time is decreased by the superposition of repeating load, as the range of stress intensity factor ΔK or the repeating frequency f increase. The reason can be explained by the promotion of corrosion reaction due to, e.g. the destruction of oxide film on the crack tip, which facilitates the invasion of hydrogen atoms into the material.

The crack propagation rate da/dt is decreased by the superposition of repeating load, and there exist two valleys of crack propagation rate minima on the da/dt vs f and da/dt vs ΔK curves. One valley corresponds to the interaction between the cyclic movement of the region with tri-axial tensile stress and the hydrogen atoms diffused from crack tip, which disturbs the concentration of hydrogen atoms. Another seems te correspond to the generation of retained compressive stress which reduces the effective stress intensity at crack tip and supresses the invasion and diffusion of hydrogen atoms.     

Anomalous properties of poly(γ-benzyl L-glutamate) film composed of unusual 7/2 helices

Poly(γ-benzyl L-glutamate) film composed of unusual 7-residue 2-turn (7/2) helices was prepared by slow casting from chloroform solution. The 7/2 helical conformation was irreversibly transformed at 84°C to the normal 18/5 conformation. In d.s.c. thermograms the transformation appeared as an endothermic first order transition with an enthalpy change of 3.4 cal g⁻¹. The viscoelastic and dielectric measurements indicated that the loss peak due to the side chain motion in this film was reduced to a great extent compared to the film of 18/5 helices. The dielectric relaxation strength dictated that there was a motional restriction in three quarters of the side chains. By comparison to a racemic mixture of poly(γ-benzyl glutamate), these anomalous properties were attributed to the stack of terminal benzyl groups of side chains (ormed in an alternating manner between neighbouring chains). The first order transition arises from the cooperative fusion of the stack and the side chains with their benzyl groups which are restricted in thermal motion. Such stacks may be facilitated by the precise ‘knob (side chain) and hole (space between side chains)’ packing which can be attained between neighbouring 7/2 helices.     

Possible mechanism for the anti-atherosclerotic action of the calcium channel blocker AE0047 in cholesterol-fed rabbits

The genetics of resistance to disease is an area of great interest in agriculturally important plant and animal species. Selective breeding for resistance to pathogens in plants, animals and insects has demonstrated that resistance and susceptibility to pathogens are controlled by both genetic and environmental factors. The immune loci causally involved in susceptibility and resistance to disease are currently unknown. However, novel enabling molecular technologies promise to assist in unravelling the genetics of the host response to infectious diseases in new ways, and ultimately to improve seed stock genetics.     

A theory of pseudo cross-link

Summary A theory of pseudo cross-link model suggests the existence of multiple links of various size composed of 116 segmental units. They possesses the heat and entropy of various magnitude giving various transition temperature, T_A for the cross-link composed of 4 segments and T_B for that of 16 segments. The glass-transition point T_g and the melting point T_m are defined by the different size of lateral multiple links. Relationships, T_m = 2 T_A and T_g = (2/3)T_m = (4/3)T_A, are derived. A wedge-type relaxation spectrum is obtained as a distribution of size of cross-links. For temperature dependence the WLF-equation is obtained.     

Measurement of heat of mixing for ammonium chloride + ammonia system at 25 °c

Heat of mixing for ammonium chloride in liquid ammonia at 25°C was determined in the concentration range 0-50 wt% NH₄Cl. It was calculated from the differential heat of solution observed in this work and the differential heat of dilution estimated from activities of solvent. A twin isoperibol calorimeter consisting of two stainless Dewar vessels was used at a relatively high pressure (up to 1.5 MPa). The accuracy of this calorimetry was examined by measuring the heat of solution for tris-(hydroxymethyl)aminomethane(THAM) in 0.1 kmol/m³ HCl at 25°C, and satisfactory agreement within 1.1% between experimental and literature value was obtained. The reproducibility for the experiment was within 2.8%.     

X-ray spectroscopy of highly ionised atoms of Ti through Zn in a dense plasma

X-ray spectra for several elements have been observed from a high-temperature plasma produced in a vacuum spark using a curved-crystal spectrometer. The transition wavelengths of the He-like resonance lines for Ti through Zn are determined for the first time under careful experimental treatments. The result is compared with theoretical predictions. The transition wavelengths of the Fe He-like resonance series lines up to 1s6p–1s² and the Kβ transition energies of Ti partially M-shell-ionised ions (Ti VI–XIII) are also determined. As a result, several satellite lines are found.