Phylogenetic position of Dictyostelium inferred from multiple protein data sets

The phylogenetic position of Dictyostelium inferred from 18S rRNA data contradicts that from protein data. Protein trees always show the close affinity of Dictyostelium with animals, fungi, and plants, whereas in 18S rRNA trees the branching of Dictyostelium is placed at a position before the massive radiation of protist groups including the divergence of the three kingdoms. To settle this controversial issue and to determine the correct position of Dictyostelium, we inferred the phylogenetic relationship among Dictyostelium and the three kingdoms Animalia, Fungi, and Plantae by a maximum-likelihood method using 19 different protein data sets. It was shown at the significance level of 1 SE that the branching of Dictyostelium antedates the divergence of Animalia and Fungi, and Plantae is an outgroup of the Animalia-Fungi-Dictyostelium clade.     

Discussion of the indentation hardness of a glass-ceramic with participate microstructure

On the basis of a theory previously developed by the authors for the indentation hardness of glass matrix, particulate composites, an attempt was made to interpret published hardness data for a ZnO-Al₂O₃-SiO₂ glass-ceramic in which gahnite (ZnAl₂O₄) crystal particles are dispersed in a glass matrix as a major crystalline phase. The elastic moduli for gahnite were estimated using both the bulk modulus-molar volume relationship and the density-Poisson's ratio relationship, established for oxide crystals. After determining the variation of the matrix Young's modulus with heat-treatment, the variation of the overall hardness with volume fraction of crystal phase as well as the crystal-size effect were discussed. The hardness behaviour of the present glass-ceramic could be interpreted well in terms of the properties and amounts of the constituent phases and the microstructural effects.     

Intraframe Image Coding by Cascaded Hadamard Transforms

Various image coding schemes have been studied for digital transmission of videophone signals. The Hadamard transform, which is now studied for the transmission of pictures such as those from satellites, has been considered too complicated for public use, though the characteristics such as the ratio of bit-rate reduction are more desirable than those of differential pulse-code modulation (DPCM). We have found a very simple scheme of the transform, where digitized videophone signals are transformed to Hadamard components all digitally just byndigital adders and some shift registers for 2ⁿth-order transform. For example, three adders are necessary for eighth-order transform. It is extendable to two-dimensional transform with ease. We have made an experimental model running in real time. Experiments and theoretical calculation have shown that 3 bits/sample are required for good picture quality in the case of two-dimensional(4 times 2)th transform and 0.5 bits more for one-dimensional eighthorder transform.     

Silica films with a single-crystalline mesoporous structure

Films of mesoporous materials attract broad interest because of their wide applicability in the fields of optics and electronics. Although many of these films have a regular local porous structure, the structural regularity has not been used practically yet because of difficulties in its control on macroscopic scales. Here, we demonstrate the preparation of mesoporous silica films whose porous structure can be described as a single crystal, that is, a long-range order of cage-like pores is maintained over centimetre scales. These films have a three-dimensional hexagonal (space group P6(3)/mmc) porous structure, and the in-plane arrangement of the pores is strictly controlled by a polymeric substrate surface that has been treated by rubbing. This new class of single-crystalline films with mesoscopic periodic structure is a significant breakthrough in bottom-up nanotechnology, and could lead to novel devices, for example, optics in a soft X-ray region, and quantum electronics.     

Formation of stable foam by the cells and culture supernatant of Gordonia (Nocardia) amarae

Gordonia amarae is the cause of foaming activated sludge. In this study, the mechanism of foam formation by G. amarae SC1 was investigated. A liquid culture of SC1 cells generated a stable foam when shaken reciprocally. This foam formation was dependent on the presence of both bacterial cells and culture supernatant. A high-molecular-weight fraction (Mw>10000) of the supernatant was capable of emulsifying n-hexadecane in addition to exhibiting foaming activity, indicating that it contains a surface-active substance(s). The bacterial cells showed a high affinity to hexadecane. This hydrophobic cell surface property might be involved in the attachment of cells to air bubbles to generate a stable foam. The results demonstrated the participation of cells and the extracellular biosurfactant in the formation and stabilization of foam in G. amarae SC1 culture.     

The data-driven microprocessor

Processor performance limitations that can be solved by data-flow processing are discussed. Data-flow-based software and multiprocessors are considered. A data-driven, 32-bit, five-chip set that performs real-time signal and distributed parallel processing without a system clock or centralized control unit is presented. Language processing and processor applications are examined     

Determination of the thermal conductivity of argon and nitrogen over a wide temperature range through data evaluation and shock-tube experiments

Reliable and well-established methods to measure the thermal conductivity of gases are available only in the moderate temperature range, namely, up to about 1000 K. In the present study, a set of the most probable thermal conductivity values of components of gaseous combustion products in a wide range of temperatures has been obtained through an optimum combination of three procedures: critical assessment of available data in the moderate temperature range, experimental determination by the shock-tube method at high temperatures, and theoretacal estimation of temperature dependence in the intermediate temperature range. Among the components of combustion products, one monatomic gas and one diatomic gas, namely, argon and nitrogen, were studied in the present paper. The shock-tube measurements have been performed in the temperature ranges 1000–4500 K for argon and 500–2200 K for nitrogen. The results of the critical evaluation and the shock-tube measurements have been combined with the aid of theoretically assumed temperature dependence of the thermal conductivity.Invited paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A.     

Study of N-nitroso compounds which have NO-release ability

Nitric oxide (NO), which plays an important role in the vital functions of organisms, is gaseous and labile molecule. Much attention has been paid to the stability and easily handling of NO donors, for careful handling of NO is required during experimental work. We synthesized a series of aromatic N-nitrosoureas and N-nitrosamides which efficiently liberates NO at room temperature. Generation of NO from the aromatic N-nitroso compounds was chemically confirmed by the trapping of NO as a nitrosyl complex of tetraphenylporphyrinatocobalt (II) and spectrophotometrically quantified by means of the Griess reaction using a newly designed test apparatus. 3,3-Dibenzyl-1-(4-tolyl)-1-nitrosourea showed the greatest NO-generating ability among the synthesized N-nitroso compounds. Further, the NO-generating ability was related to the reciprocal of the ID50 value for growth inhibition of cultured L-5178Y cell by the aromatic N-nitroso compounds.     

Accumulation of pyrraline-modified albumin in phagocytes due to reduced degradation by lysosomal enzymes

Previous studies suggested that the interaction between proteins modified by advanced glycation end products (AGEs) and cells, such as macrophages, may be involved in diabetic angiopathy. Pyrraline is one of the AGEs and known to be elevated in plasma of diabetic rats and humans, and is present in vascular lesions of diabetic and elderly subjects. We examined whether modification of albumin by pyrraline influences its degradation by macrophage-like cell line, P388D1 cells. Degradation of pyrraline-modified albumin by these cells was diminished, causing accumulation of the albumin in these cells. The susceptibility of pyrraline-modified albumin to lysosomal proteolytic enzymes was reduced by approximately 40% in vitro, while lysosomal activity in the cells per se was not affected. This phenomenon was also observed when human monocytes were used instead of P388D1 cells. Our results suggest that accumulation of pyrraline-modified albumin in P388D1 cells is due to the reduced susceptibility of the protein to lysosomal enzymatic degradation. Such alterations in the interaction between AGEs-modified protein and phagocytes may contribute to angiopathy in elderly subjects and patients with diabetes.     

Material Flow Analyses of Noncircular-Shaped Granular Media Using Discrete Element Methods

The mathematical development and application of two discrete element methods for analyzing the material flow of granular media is described. These two discrete element methods model the noncircular-shaped particles with analytical surface representations. 2D particles are modeled with a superquadric equation and 3D particles as ellipsoids. Two examples are then presented to illustrate the applicability of these techniques in engineering analysis. These examples include (1) flow of particulate media in a rotating drum; and (2) flow of ore material in an inclined ore pass system.