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The ploidy status of Acipenser mikadoi was examined using nuclear DNA contents, karyotypes and fluorescence in situ hybridization ( FISH) with 5.8S + 28S rDNA as a probe. In flow-cytometrically sorted specimens with 8.2-9.1 pg DNA content per somatic cell, i.e. genetic diploid, the best informative metaphase with 268 chromosomes had 80 biarmed meta- or submetacentric ( M or SM) chromosomes, 48 monoarmed telocentric ( T) chromosomes and 140 microchromosomes. In genetic triploid specimens with 12.6-13.0 pg DNA content, the best informative metaphase with 402 chromosomes showed 120 biarmed M or SM, 72 monoarmed T chromosomes and 210 microchromosomes. The rDNA FISH detected a maximum 18 and 27 signals in the diploid and triploid A. miakdoi, respectively. The obtained findings thus corroborated a clear parallel between nuclear DNA contents and karyological or FISH profiles in the genetic diploid and triploid specimens, suggesting 1.5 times chromosome complements of diploid counterparts or three sets of homologues in the triploid sturgeons. Moreover, the estimated genome size and the observed molecular cytogenetic features in the diploid A. mikadoi strongly suggest that this species is a member of a functional tetraploid group recently proposed in the literature. [ABSTRACT FROM AUTHOR]

On 19 December 2009, the eastern part of Taiwan at approximate depth of 45 km was struck by a strong earthquake (Mw = 6.4). The epicenter was located about 20 km away from the Hualien (HLN) station in Taiwan. By analyzing data from the HLN station and Amami Oshima (AMA) in Japan as a remote reference, the geomagnetic east-west (D) and vertical (Z) components recorded at the HLN station are showing no correlation with those at the AMA station in December 2009. Anomalous variations of ∼10-15 nT started about one week before the occurrence of the earthquake and lasted for about two weeks. Also, an enhanced ULF signal in the range of Pc 3 (10-40 s) was observed a few days before the onset of the earthquake. Moreover, the polarization ratio (Z/H (north-south component)) of the Pc 3 amplitude at the HLN station decreased a few days preceding the earthquake. The mechanism behind these anomalous variations is not fully understood. However, we expect that crustal stress perturbations and underground conductivity changes associated with the earthquake played an important role for generating such observed geomagnetic variations. [ABSTRACT FROM AUTHOR]