Electric and magnetic phenomena observed before the volcano-seismic activity in 2000 in the Izu Island Region, Japan.

Significant anomalous changes in the ultra low frequency range (approximately 0.01 Hz) were observed in both geoelectric and geomagnetic fields before the major volcano-seismic activity in the Izu Island region, Japan. The spectral intensity of the geoelectric potential difference between some electrodes on Niijima Island and the third principal component of geomagnetic field variations at an array network in Izu Peninsula started to increase from a few months before the onset of the volcano-seismic activity, culminating immediately before nearby magnitude 6 class earthquakes. Appearance of similar changes in two different measurements conducted at two far apart sites seems to provide information supporting the reality of preseismic electromagnetic signals.

Geoelectric potential changes: possible precursors to earthquakes in Japan.

Whether electromagnetic precursors to earthquakes (EQs) exist is an important question not only for EQ prediction but also for understanding the physical processes of EQ generation. Slow transient geoelectric potential changes have been observed before several recent EQs in Japan. In most cases, they appeared 1-19 days before the EQs, and their duration and intensity were several minutes to 1 h and 1-2 mV/100 m. The changes appeared before five of all six EQs with magnitude >/= 5 that occurred within 20 km of our stations during the observation period. Changes were also detected at greater epicentral distances (up to 75 km) before two other EQs, including one EQ of magnitude 4.7, which was preceded by a signal simultaneously recorded at three widely separated stations. These geoelectric potential changes have been distinguished through the following criteria from a multitude of other changes, which were noise of various origins. (i) The selected changes were proportional in amplitude to the length of the recording station's short ( approximately 100 m) dipoles and were simultaneously detected also on long (1-10 km) dipoles when the latter were in operation. (ii) No such changes occurred during the observation period that were not followed by EQs. Although the EQ precursory nature of these geoelectric potential changes is admittedly unproven, it seems that the present results warrant continued serious research into the occurrence, generation, and transmission of these signals and their possible causal relationship to EQs.

The C-terminal region of the P3 structural protein of rice dwarf phytoreovirus is important for P3-P3 interaction.

Using a random peptide library designed for the yeast two-hybrid system, we identified a peptide that binds strongly to the P3 structural protein of rice dwarf phytoreovirus (RDV). The amino acid sequence of the peptide showed a high homology to the C-terminal region of P3. C-terminally truncated P3 lost its ability to interact with authentic P3. Our observations suggest that the C-terminal region of P3 is important for the P3-P3 interaction, which forms the core shell structure of RDV.