Search Results - (Author, Cooperation:H. Toh)

2011-01-29

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Acetates/*metabolism ; Animals ; Bifidobacterium/genetics/*metabolism ; Cercopithecus aethiops ; Escherichia coli Infections/microbiology/*prevention & control ; Escherichia coli O157/*physiology ; Gene Expression Profiling ; Genome, Bacterial ; Mice ; Molecular Sequence Data ; Vero Cells

1089-7550

AIP Digital Archive

Physics

This article develops the theoretical foundation for the temperature–entropy (T–s) diagram for irreversible absorption chillers that employ either a volatile or nonvolatile working pair. The representation of a real absorption refrigeration cycle on a T–s diagram can directly depict the energetic superiority of one design over another. For practical usage, this diagrammatic approach only requires as inputs the inlet and outlet state points that can be computed based on the corresponding temperatures, pressures, and component concentrations of each of the heat-and-mass exchanger modules within a chiller system and can therefore also be employed as a useful tool for system analysis and diagnosis. The same method is also applicable to any continuously operating thermodynamic system that is wholly or partially driven by thermal power. © 2000 American Institute of Physics.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Phosphoenolpyruvate carboxylase is an enzyme involved in a wide variety of important metabolic pathways of plants such as anaplerotic reactions and C4 and CAM photosynthetic pathways. The accumulation of molecular sequence data of phosphoenolpyruvate carboxylases has enabled us to investigate the function and molecular evolution of the enzymes by computer-assisted sequence comparison. Here we report the results of sequence comparison of phosphoenolpyruvate carboxylases: (1) Phosphoenofpyruvate carboxylases were classified into four groups; a subgroup of bacterial enzymes and three subgroups of plants enzymes. (2) The divergence time of the monocot enzymes involved in the C4 pathways was roughly estimated to be 150—300 million years. On the other hand, the phylogenetic tree of the enzymes suggested that those for the dicot enzymes involved in the C4 and CAM pathways might be close to the divergence time between the monocots and the dicots. (3) The evolutionary positions of the enzymes prevalent in roots or root nodules were identified. (4) Although sorghum and maize contained at least three genes for the enzymes in their genomes, the rates of amino acid substitution of the enzymes were different from gene to gene. The difference could not be explained by either lineage effects nor bias in base contents.

Electronic Resource

0006-291X

[abr] LT; leukotriene ; [abr] PCMB; p-chloromercuribenzoic acid

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

[abr] LT; leukotriene ; [abr] PCMB; p-chloromercuribenzoic acid

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0012-821X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Geosciences

Physics

Electronic Resource

0014-5793

Ab initio molecular orbital calculation ; Mg^2^+ ; Ribozyme

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0014-5793

5'-3'-Exonuclease ; Bacteriophage T7 ; DNA polymerase I ; DNA primase ; Helix-destabilizing protein ; Homology

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0014-5793

Epidermal growth factor ; Prostaglandin endoperoxide synthase ; Sequence homology

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0031-9201

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Geosciences

Physics

Electronic Resource

0022-5193

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0921-8777

Action spectrum for photoreactivation ; DNA photolyase ; Drosophila photorepair gene ; Evolution of photorepair gene ; Tissue- and stage-specific gene expression ; UV damage

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

0090-6980

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Electronic Resource

1573-0581

Electromagnetic induction ; ocean bottom magnetometer ; 85° E ridge ; Ninety East ridge ; geomagnetic depth sounding ; vertical gradient sounding ; thin-sheet modelling ; 3-D forward modelling

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract Seafloor magnetometer array experiments were conducted in the Bay of Bengal to delineate the subsurface conductivity structure in the close vicinity of the 85° E Ridge and Ninety East Ridge (NER), and also to study the upper mantle conductivity structure of the Bay of Bengal. The seafloor experiments were conducted in three phases. Array 1991 consisted of five seafloor stations across the 85° E Ridge along 14° N latitude with a land reference station at Selam (SLM). Array 1992 also consisted of five seafloor stations across 85° E Ridge along 12° N latitude. Here we used the data from Annamalainagar Magnetic Obervatory (ANN) as land reference data. Array 1995 consisted of four seafloor stations across the NER along 9° N latitude with land reference station at Tirunelveli (TIR). OBM-S4 magnetometers were used for seafloor measurements. The geomagnetic Depth Sounding (GDS) method was used to investigate the subsurface lateral conductivity contrasts. The vertical gradient sounding (VGS) method was used to deliniate the depth-resistivity structure of the oceanic crust and upper mantle. 1-D inversion of the VGS responses were conducted and obtained a 3-layer depth-resistivity model. The top layer has a resistivity of 150–500 Ωm and a thickness of about 15–50 km. The second layer is highly resistive (2000–9000 Ωm) followed by a very low resistive (0.1–50 Ωm) layer at a depth of about 250–450 km. The 3-component magnetic field variations and the observed induction arrows indicated that the electromagnetic induction process in the Bay of Bengal is complex. We made an attempt to solve this problem numerically and followed two approaches, namely (1) thin-sheet modelling and (2) 3-D forward modelling. These model calculations jointly show that the observed induction arrows could be explained in terms of shallow subsurface features such as deep-sea fans of Bay of Bengal, the resistive 85° E Ridge and the sea water column above the seafloor stations. VGS and 3-D forward model responses agree fairly well and provided depth-resistivity profile as a resistive oceanic crust and upper mantle underlained by a very low resistive zone at a depth of about 250–400 km. This depth-range to the low resistive zone coincide with the seismic low velocity zone of the northeastern Indian Ocean derived from the seismic tomography. Thus we propose an electrical conductivity structure for the oceanic crust and upper mantle of the Bay of Bengal.

Electronic Resource

1573-0581

EMRIDGE ; electromagnetic induction ; Juan de Fuca Ridge ; Blanco Fracture Zone ; geomagnetic depth sounding ; magnetotellurics ; thin-sheet modelling

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract From July to November 1988, a major electromagnetic (EM) experiment, known as EMRIDGE, took place over the southern end of the Juan de Fuca Ridge in the northeast Pacific. It was designed to complement the previous EMSLAB experiment which covered the entire Juan de Fuca Plate, from the spreading ridge to subduction zone. The principal objective of EMRIDGE was to use natural sources of EM induction to investigate the processes of ridge accretion. Magnetotelluric (MT) sounding and Geomagnetic Depth Sounding (GDS) are well suited to the study of the migration and accumulation of melt, hydrothermal circulation, and the thermal evolution of dry lithosphere. Eleven magnetometers and two electrometers were deployed on the seafloor for a period of three months. Simultaneous land-based data were made available from the Victoria Magnetic Observatory, B.C., Canada and from a magnetometer sited in Oregon, U.S.A. Changes in seafloor bathymetry have a major influence on seafloor EM observations as shown by the orientation of the real GDS induction arrows away from the ridge axis and towards the deep ocean. Three-dimensional (3D) modelling, using a thin-sheet algorithm, shows that the observed EM signature of the Juan de Fuca Ridge and Blanco Fracture Zone is primarily due to nonuniform EM induction within the ocean, associated with changes in ocean depth. Furthermore, if the influence of the bathymetry is removed from the observations, then no significant conductivity anomaly is required at the ridge axis. The lack of a major anomaly is significant in the light of evidence for almost continuous hydrothermal venting along the neo-volcanic zone of the southern Juan de Fuca Ridge: such magmatic activity may be expected to have a distinct electrical conductivity signature, from high temperatures, hydrothermal fluids and possible melt accumulation in the crust. Estimates of seafloor electrical conductivity are made by the MT method, using electric field records at a site 35 km east of the ridge axis, on lithosphere of age 1.2 Ma, and magnetic field records at other seafloor sites. On rotating the MT impedance tensor to the principal axis orientation, significant anisotropy between the major (TE) and minor (TM) apparent resistivities is evident. Phase angles also differ between the principal axis polarisations, and TM phase are greater than 90° at short periods. Thin-sheet modelling suggests that bathymetric changes accounts for some of the observed 3D induction, but two-dimensional (2D) electrical conductivity structure in the crust and upper mantle, aligned with the ridge axis, may also be present. A one-dimensional (1D) inversion of the MT data suggests that the top 50 km of Earth is electrically resistive, and that there is a rise in conductivity at approximately 300 km. A high conductivity layer at 100 km depth is also a feature of the 1D inversion, but its presence is less well constrained.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Adult landlocked Japanese salmon, O. masou, of about 190 mm total length, were maintained in tanks of circulating tap water at 15 C. Ecological and ethological characteristics of this species have been observed by us in the field and aqauarium (90x45 x 45 cm). Five fish were stunned by a blow to ...

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Strontium to calcium ratios were observed along longitudinal sections of statoliths of nine neon flying squid, Ommastrephes bartrami (LeSueur, 1821), including three mature females (422 to 454 mm mantle length, ML; 207 to 306 d old) obtained from the North Pacific (27–35°N; 144–150°E) during winter and six immature males and females (187 to 226 mm ML; 126 to 164 d old) collected from 39°N; 145°E and 39°N; 169°W during summer. The distances between the nucleus (core) and the edge of the dorsal dome were approximately 660 to 690 μm in mature females and 450 to 510 μm in the immature squid. Sr/Ca ratios were determined at intervals of 30 μm between the nucleus and edge of the dorsal dome. Sr/Ca ratios were higher in areas near the nuclei and peripheral portions of the dorsal dome than in the middle portions of the statoliths (270 to 420 μm from the nuclei, corresponding to ages of 60 to 90 d) in mature females; thus a U-shaped pattern was evident. Sr/Ca ratios in the six immature squid decreased from nucleus to the dorsal dome; in three squid the ratios slightly increased toward the dorsal dome edge. The observed Sr/Ca ratios in immature squid were considered to represent younger portions of the U-shaped pattern. In the present study we discuss this pattern in relation to environmental and biological conditions of O. bartrami, which undertakes seasonal migrations between spawning grounds in the Subtropical Domain and feeding grounds in the Subarctic Domain and Transitional Zone in the North Pacific Ocean. Although Sr/Ca ratios are potentially affected by ambient water temperature and ontogenetic conditions, including somatic growth and statolith growth, it was impossible to evaluate each environmental and biological effect separately, as variations in these factors are complicated and effects could be interdependent.

Electronic Resource

0003-276X

Gingiva ; Junctional epithelium ; Rodents ; Mucosa ; Differentiation ; Blood group antigens ; Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Medicine

Background: The junctional epithelium (JE) attaches the gingiva to the non-vital tooth surface and has other unusual properties which protect the underlying periodontal tissues. The JE differs from other gingival and oral epithelia in its unusual expression of cytokeratins typical of both stratifying and of simple èpithelia, a phenotypic pattern possibly related to its specialized functions.Methods: The patterns of differentiation of rodent gingival and other epithelia were examined using monoclonal antibodies against various glycoconjugates which are expressed on epithelial cell surfaces and provide an alternative marker system for regionally-differing patterns of cell maturation.Results: Markers that are typical of basal cells in other stratifying epithelia were expressed by all cell strata of JE. JE lacked differentiation markers typical of other stratifying oral epithelia but showed suprabasal expression of markers typically expressed by simple epithelia and specialized epithelia, such as taste buds.Conclusions: The phenotype of rodent JE differs from that of other oral epithelia and the pattern of differentiation assessed by its expression of glycoconjugates parallels that for other phenotypic markers, such as cytokeratins. Differentiation of rodent JE is similar to that of human JE. The functional significance of these patterns of expression is not yet clear but the markers characterizing this unusual epithelium in rodents may be associated with its behavior in periodontal disease and of value to experimental studies of its development.© 1995 Wiley-Liss, Inc.

4 Ill.

Electronic Resource