Repeated GPS surveys in the Mariana Islands show that the Mariana block is moving apart from the Philippine Sea plate. The velocities of the islands relative to the Philippine Sea plate range from ...about 15 mm/yr in the northern islands to about 45 mm/yr near Guam. The data also suggest convergence rates for the Mariana forearc with respect to the Pacific plate of 35–45 mm/yr at 19°N increasing to 55–70 mm/yr at 13.5°N. In addition, the velocity vectors show a slight north‐south expansion of the arc. The estimated location of the Euler pole of the Mariana forearc with respect to the Philippine Sea plate is well south of the geographical point where the back‐arc basin narrows to zero width.
To investigate tectonic deformation in the western Pacific, a continuous GPS tracking network has been established, and named the Western Pacific Integrated Network of GPS (WING). Between 1995 and ...March 1997 we establised ten new sites. Data for the period July 1995 to October 1996 were analyzed, together with data from International GPS Service for Geodynamics (IGS) global sites, to estimate daily coordinates. A fiducial‐free approach was used to obtain the most accurate baseline estimates. To fix the estimated coordinates to the terrestrial reference frame, the Tsukuba IGS site is assumed to be moving westward relative to the stable Eurasian continent at ∼2 cm/yr according to Heki's 1996 estimate. We find that: (1) velocities of sites well within oceanic plates are in good agreement with rigid plate motion models; (2) sites close to plate boundaries are all affected by the deformation at those boundaries, among which back‐arc rifting (spreading) is clearly visible at the Mariana and Okinawa troughs; (3) sites in eastern Asia are moving east to east‐southeast relative to the stable Eurasian continent, suggesting long distance effects of the northward collision of India with Asia.
P0 glycoprotein is the abundant membrane protein of myelin of the peripheral nervous system. We report now the statistical design of the crystallization experiments; based on our belief that ...important information regarding supersaturation of protein or its solubility nature, as well as metastable state, nucleation or precipitation, are hidden in the trials in which no crystals grow. It is possible to work out this information when the whole set of experiments is designed in such a way as to allow statistical analyses. We selected seven factors, which we believe to be important for crystallization: protein concentration, pH of buffer, nature of precipitant, concentration of precipitant, nature of detergent, additives and temperature. The experimental matrix and detailed work sheet to make 148 solutions having random but balanced combination of these levels were calculated using the program DESIGN. A visual evaluation of crystallization drops was performed using light microscopy. We were able to plot the precipitation boundary diagram. Based on this diagram we have eliminated factors (and levels) that were driving the protein into precipitation. It is known that the precipitation boundary is related to the solubility curves for protein crystals, in the neighborhood of which nucleation and further crystallization is most likely to occur. These conditions are currently being refined to identify important factors (or its levels) that can be crucial in obtaining large and well diffracting crystals. Full-length P0 protein has never been crystallized for structural determination.
P0 is an abundant myelin glycoprotein of peripheral nerves of vertebrates. Various point mutations of this protein are responsible for hereditary neuropathies. In this paper we described purification ...of P0 glycoprotein using SDS and a metal chelate affinity chromatography. Purified myelin fraction from bovine spinal roots in 0.5% SDS, 0.5 M NaCl, 50 mM Tris-HCl, pH 7.4 is filtered and applied directly to the Cu super(2+)-immobilized affinity chromatography column, equilibrated with the same buffer. After eluting a void volume (or pass through) fraction, P0 protein was eluted by the same buffer but without salt. To remove contamination from the eluent, further purification is continued on a Concanavalin-A coupled agarose column. We purify within two days, 30 mg of P0 protein of apparent molecular weight 27 kDa. The method can be used to purify recombinant or mutated P0 protein found in severe pathologies.
P0 is an abundant myelin glycoprotein of peripheral nerves of vertebrates. Various point mutations of this protein are responsible for hereditary neuropathies. In this paper we described purification ...of P0 glycoprotein using SDS and a metal chelate affinity chromatography. Purified myelin fraction from bovine spinal roots in 0.5% SDS, 0.5 M NaCl, 50 mM Tris-HCl, pH 7.4 is filtered and applied directly to the Cu2+-immobilized affinity chromatography column, equilibrated with the same buffer. After eluting a void volume (or pass through) fraction, P0 protein was eluted by the same buffer but without salt. To remove contamination from the eluent, further purification is continued on a Concanavalin-A coupled agarose column. We purify within two days, 30 mg of P0 protein of apparent molecular weight 27 kDa. The method can be used to purify recombinant or mutated P0 protein found in severe pathologies.
PASII/PMP22 protein (mol. wt 22 kDa, pI 8.8) is an abundant and extremely hydrophobic glycoprotein of PNS myelin which is solubilized effectively by SDS. In humans, this protein is involved in ...hereditary neuropathies. Here we describe a simple method for purification of PASII/PMP22, suitable for crystallization trials. We usually obtained 10-20 mg PASII/PMP22 from 10 g bovine spinal roots. It is notable, that the original protocol was designated for purification of P0 myelin glycoprotein, and purification of PASII/PMP22 is a bonus. Extensive crystallization trials are in progress.
The heterogeneity and anisotropy in the lower mantle such as seismic P wave velocities and geoid anomalies point to a fundamental Pacific/African bipolarity. The ridge/subduction zone systems have ...some relationship with the hemispheric hotspots grouped through the mantle convection and so may have nearly antipodal axes under the influence of convection flow. A global seismicity map suggests that most of earthquake epicenters are distributed on a part of great circles over the Earth's sphere. We propose a method for detecting great circles from the global epicenter distribution by using the Hough transformation. As a result, we extract two dominant great circles which intersect perpendiculaly each other at the equator as an axis of symmetry. One of these two great circles is passing through the northern part of the circum-Pacific seismic zone and the Africa-Antarctic plate boundary, while the other is passing through the Eurasian seismic belt. The reason of the orthogonality and the symmetry of these two great circles to the equator is discussed qualitatively in comparison with the long-wavelength geoidal anomalies and the Earth's rotation.
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